SOCRATES

"The unexamined life is not worth living."

Born: about 470 BC in Athens

Died: 399 BC in Athens (aged about 71) 

• Credited as one of the founders of Western philosophy
• First moral philosopher in the Western tradition
• Known for the Socratic Method
• Credited with saying "The unexamined life is not worth living"
• Plato was a disciple (student) of Socrates

DIOGENES

"I am a citizen of the world."

Born: around 412 BC in Sinope

Died: 323 BC in Corinth (aged about 89)

• A controversial figure
• Known for ascetic, or very simple, lifestyle
• Called himself a cosmopolitan and a citizen of the world, rather than claiming allegiance to one place
• Diogenes' ideas nfluenced Alexander the Great and the development of Stoicism
• Known for Cynic Philosophy and Cosmopolitanism

PLATO

"Wonder is the feeling of a philosopher, and philosophy begins in wonder."

Born: 420s BC in Athens

Died: 348 or 347 BC in Athens (age c. 80)

• Founded the Academy, the first institution of higher learning in the Western world
• Considered the founder of Western political philosophy
• Was a disciple of Socrates and influenced also influenced by Pythagoras
• Aristotle was a disciple of Plato
• Known for allegories (such as the Allegory of the Cave), and works including the Republic and Dialogues

ARISTOTLE

"In all things of nature there is something of the marvelous."

Born: 384 BC in Stagira, Chalcidian League
Died: 322 BC in Euboea, Macedonian Empire (aged approx. 62)

• Was a disciple of Plato
• Founder of the Lyceum, the Peripatetic school of philosophy, and the Aristotelian tradition
• Taught Alexander the Great and Theophrastus
• Known for Aristotelian philosophy, Syllogism, Theory of the soul, Virtue ethics
• His philosophy has had influence on almost every form of knowledge in the West and continues to be a subject of philosophical discussion.

EPICURUS

"The greatest reward of righteousness is peace of mind."

Born: February 341 BC in Samos, Greece
Died: 270 BC in Athens, Greece (aged about 72)

• Epicurus and his followers were known for eating simple meals and discussing philosophy.
• Openly allowed women to join the school as a matter of policy.
• For Epicurus, the purpose of philosophy was to help people be happy.

ZENO

"We have two ears and one mouth, so we should listen more than we say."

Born: 334 BC in Citium, Cyprus
Died: 262 BC in Athens (aged about 72)

• Zeno was the founder of the Stoic school of philosophy.
• Based on the moral ideas of the Cynics, Stoicism emphasized \peace of mind gained from living a life of virtue in accordance with nature.
• Also known for ideas such as the three branches of philosophy (physics, ethics, logic), rationality of human nature, and world citizenship